curl --request POST \
  --url https://api.iotools.cloud/v1/tool/density-calculator \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "solveFor": "density",
  "density": "7.85",
  "densityUnit": "gcm3",
  "mass": "1000",
  "massUnit": "g",
  "volume": "1",
  "volumeUnit": "l"
}
'

{
  "tool": "density-calculator",
  "tool_version": "1.0.2",
  "outputs": {
    "results": [
      {
        "quantity": "Density",
        "value": "1 g/cm³ (= g/mL)",
        "other-units": "1000 kg/m³ · 1 kg/L · 62.428 lb/ft³ · 0.0361273 lb/in³"
      },
      {
        "quantity": "Mass",
        "value": "1 kg (kilograms)",
        "other-units": "1000 g (grams) · 1000000 mg (milligrams) · 2.20462 lb (pounds) · 35.274 oz (ounces) · 0.001 t (metric tons) · 0.00110231 US ton (short ton)"
      },
      {
        "quantity": "Volume",
        "value": "1 L (liters)",
        "other-units": "0.001 m³ (cubic meters) · 1000 mL (= cm³) · 0.0353147 ft³ (cubic feet) · 61.0236 in³ (cubic inches) · 0.264172 US gal (gallons) · 0.219969 UK gal (imperial gallons)"
      }
    ],
    "breakdown": "Solving for: Density\ndensity = mass ÷ volume\ndensity = 1 g/cm³\nmass = 1 kg\nvolume = 1 L"
  },
  "credits_used": 5,
  "credits_remaining": null
}